/**
 *       Copyright (c) 2012 Lukas Zaruba
 *
 *   This file is part of Robot Playground.
 *
 *   Robot Playground is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   Robot Playground is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with Robot Playground. If not, see <http://www.gnu.org/licenses/>.
 */
package net.zarubsys.commons.scripting.functions.internal;

import java.util.Iterator;
import java.util.List;

import net.zarubsys.commons.scripting.IScriptFunction;
import net.zarubsys.commons.scripting.ParsedStatement;
import net.zarubsys.commons.scripting.ScriptingEnvironment;
import net.zarubsys.commons.scripting.ScriptingException;
import net.zarubsys.commons.utils.StringUtils;

/**
 * Based on scripting language from Media Solutions Slovakia, a.s.
 * @author Lukas Zaruba, lukas.zaruba@gmail.com
 */
public class SwitchFunction implements IScriptFunction {

    public String getName() {
        return "switch";
    }

    public int getMinArgsNum() {
        return 2;
    }

    public int getMaxArgsNum() {
        return -1;
    }

    public Object execute(ScriptingEnvironment env, List<ParsedStatement> args) throws ScriptingException {
        String switchVal = StringUtils.toString(args.get(0).execute(env));
        Iterator<ParsedStatement> iter = args.listIterator(2);
        while (iter.hasNext()) {
            ParsedStatement st = iter.next();
            if (!iter.hasNext()) {
                throw new ScriptingException("Insufficent number of arguments", env.getCurrentScriptLocator());
            }
            ParsedStatement caseSt = iter.next();
            String caseVal = StringUtils.toString(st.execute(env));
            if (((switchVal == null) && (caseVal == null)) ||
            ((switchVal != null) && switchVal.equals(caseVal))) {
                return caseSt.execute(env);
            }
        }
        return args.get(1).execute(env);
    }

}
